1. Field of the Invention
The present invention relates to a method, system, and program for defining asset classes in a digital library.
2. Description of the Related Art
In current relational database art, data is organized into logical arrangements, such that an instance of an object type having various attributes comprises a record or row in a table for the object type and each attribute of the object type instance is stored in a column of the table in that row for the object type instance. A relational database also allows for relationships between tables, such that an attribute for an object type in one table may map to an object type maintained in another table. For instance, a sales table may have as an attribute a store location. A separate store location table may have as attributes for each store location information on that store, such as address, manager, etc. In this way, the store table maintains information that may be found in many of the records in the sales table.
Relational databases are very useful when the objects have well defined and static relationships with their attributes. However, for certain types of data and libraries, the type of information stored with an object type may be constantly changing and the relationship an object type has with other object types may also be constantly evolving. Moreover, multiple variations of any object type may be created as the object evolves. Using a traditional relational database scheme would require constantly reconfiguring the current set of tables and their relationships. Further, any queries would also have to be modified to search any additional columns in existing tables or new tables that are added.
For these reasons, there is a need in the art to provide improved techniques for managing the storage and relationship of data in a digital library.